Pebble-mill.



No. 792,778. 7 v PATENTED JUNE 20, 1905. W. A. KUNEMAN.

PEBBLE MILL.

APPLIOATION FILED APR.26,1904.

2 SHEETSSHEET 1.

No. 792,778 PATENTED JUNE 20, 1905. W. A. KONLMAN.

PEBBLE MILL.

APPLICATION FILED APR. 25, 1904.

2 SHEETS-SHEET 2.

me res rrrzn Patented June 20, 1905.

WILLIAM A. KONEMAN, OF CHICAGO, ILLINOIS.

PEBBLE-MILL.

SPECIFICATION forming part of Letters Patent No. 792,778, dated June 20, 1905.

Application filed April 25, 1904:. Serial No. 204,701.

To a 1071/0717, it may concern:

Be it known that I, WVILLIAM A. KONEMAN, a citizen of the United States, residing at Chi: cago, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Pebble-Mills, of which the following is a specification.

My invention relates to improvements in pulverizers of the type commonly known as pebble-mills, in which the material to be pulverized is subjected in a rotating cylinder to the grinding action of pebbles ofharder material.

My object is to provide such a pulverizer of improved construction whereby the capacity of the cylinder is increased, the grinding action of the pebbles is enhanced, and the power necessary for rotating the cylinder is reduced.

Referring to the drawings, Figure 1 is a longitudinal section of my improved pebblemill, the section being taken on line 1 in Fig. 2; and Figs. 2 and 3 are sections taken on lines 2 and 3 in Fig. I.

A is a base-frame provided with bearingblocks B for antifriction-rollers C (l.

D is a cylinder provided at one end portion with a head E, having a feed-opening a adjacent to the cylinder-wall, thus far to one side of its center, and provided at its opposite end portion with a head F, formed with numerous perforations l). Fastened to the head portion E is a casing G, having a central feed-chamber c and a continuous spiral feeding-conduit (jr, extending from the chamber 0 and communicating at its outer end with the eccentric inlet-opening a to the cylinder. At the opposite end of the cylinder beyond the head F is a casing H, having a chamber 1, communicating at one side through an opening It with a spiral dischargirig-conduit H, terminating at the center in a flaring annular outlet-chute d. The means for discharging the pulverized material is thus very similar to the means shown in Patent No. 560,856, granted to me May 26, 1896. The cylinder D near its middle is surrounded by a rack 7), and toward opposite ends it has circumferential rails or tracks ZZ,engaged by the supporting-wheels C.

Extending through a central flanged opening (Z to the chamber 0 is the inlet-chute 6,

leading from a stationary feed-hopper I, and the cylinder is rotated in a common manner by power applied to the annular rack in. The hopper I is upon a slidingly-adjustable support I, and the chute a has a flange f, which forms a cap for the opening (Z, against which the flange about said opening turns.

As hitherto commonly constructed pebblemills of this type have had a feed-opening at the center of one end, through which material to be pulverized was fed in various ways. Owing to the location of such feed-opening, the cylinder could only receive material to a height usually somewhat below the plane of the center of rotation of the cylinder. In the rotation of the cylinder the mass in the cylinder, consisting of the pebbles and material to be ground, would when the feeding is thus performed assume substantially the position indicated by the dotted line out in Fig. 2. A dotted line a, drawn from the vertical plane of the center of rotation of the cylinder, defines the triangle or space containing that portion of the mass which, lying equally on opposite sides of the vertical plane of the center of rotation, is balanced in the cylinder. The mass in the triangular space q indicates the portion of the mass the weight of which must be lifted in the rotation of the cylinder. Thus it will be seen that in pebble-mills as hitherto constructed the mass which it is necessary to lift in turning the cylinder is greatly in excess of the balanced mass, and, furthermore, that less than half the capacity of the cylinder at the most is utilized. In my improved construction the mass is fed through the hopper l. to the chamber 0, and in the rotation of the cylinder in the direction of the arrow, Fig. 3, a portion of the mass in each revolution enters the spiral conduit G and is directed thereby to the opening 0. Thus the cylinder may be filled automatically nearly to its full capacity. The dotted line r in Fig. 2 indicates the inclined plane which the upper surface of the mass will assume while the cylinder is being rotated. The dotted line .9, drawn at right angles to the line 9* from the vertical plane of the center of rotation, shows beneath said lines a triangular space, which extending equally to opposite sides of the said vertical plane indi cates the proportion of the mass that is balanced, and the space above the line 8 indicates the proportion of the mass the weight of which must be lifted by the cylinder in its rotation. It will be seen that in my improved pebble-mill a comparatively small per cent. of the mass has to be lifted in the rotation of the cylinder. By thus increasing the capacity of the cylinder a greater number pebbles may be employed in the mill and -a larger quantity of material to be treated may be operated upon at one time. Furthermore, the power required to turn the cylinder is proportionately decreased.

In the end portion of the spiral conduit G adjacent the opening a I provide a flap or non-return valve 6, which permits the pocket or end portion of the conduit to fill from the spiral, but prevents any escape of the material from the said pocket under any circumstances, Except through the opening a, into the cylin- The perforations 7) in the head F are of a diameter which preclude the passage through them of the pebbles, while permitting the pulverized material to enter the chamber g. In the rotation of the cylinder the pulverized material entering the opening it to the spiral conduit H is moved centripetally and discharged through the flaring outlet 6. To control the amount of discharge, the opening it is provided with asuitable valve it, which may be operated by a screw 71.

The material withdrawn from the chamber 0 through the conduit G is moved during the rotation of the cylinder centrifugally to the opening a and discharged into the cylinder, and in practice the valve lb may be so adjusted with reference to the feed to the cylinder through the opening a that the discharge may be caused to be faster or slower than the feed when desired to raise or lower the level of material in the cylinder, and thereafter a practically constant level may be maintained in the cylinder to a height when desired matcrially above its center of rotation.

Besides the advantages stated of feeding the cylinder at a point near its circumference my improved feeding means possesses other desirable features. Whether the central feedchamber (6 is full or only partly full an equal amount of material to be pulverized will be positively taken by the worm or spiral conduit G from the chamber 0 in each revolution and discharged into the cylinder. Thus the feed to the cylinder does not vary, and by regulating the valve it at the outlet, as stated, a practically uniform level of material may be maintained in the cylinder.

lVhile I prefer to construct my improvements throughout as shown and described, they may be variously modified in the matter of details without departing from the spirit of my invention as defined by the claims.

What I claim as new, and desire to secure by Letters Patent, is

1. In a pebble-mill, the combination of a r0tatably-supported cylinder having a feedopening in an eccentric position in one end, a central feed-chamber on said end with means for feeding thereto material to be ground in the cylinder, a spiral conduit on said cylinder end extending from said chamber to said feedopening to discharge into the latter, and centripetally-acting discharging means for said material on the opposite end of the cylinder, substantially as and for the purpose set forth.

2. In a pebble-mill, the combination with a rotatably-supported cylinder provided with a head and feed-opening, at one end, toward its circumference, of means, for forcing the material to be treated into the cylinder through said opening, comprising a casing on said cylinder-head, a chamber in the center of the easing having an inlet for the material to be treated, a spiral feeding-conduit extending from said chamber to said feed-opening, and a non-return valve in said conduit, substantially as and for the purpose set forth.

3. In a pebble-mill, the combination of a rotatably-supported cylinder provided at one end with a head and toward its circumference with a feed-opening, a casing on said head, a chamber in the center of the casing having an inlet for the material to be treated, a spiral feeding-conduit extending from said chamber to said feed-opening, a screen on the opposite end of the cylinder, a casing on the cylinder beyond said screen having a chamber, a cen tral discharge-opening, and a spiral centripetally-discharging conduit extending from said chamber to said discharge-opening, and a discharge-controlling valve for said dischargingconduit, all constructed and arranged to operate substantially as and for the purpose set forth.

WVILLIAM A. KONEMAN.

In presence of- WALTER N. \VINBERG, M. S. MAOKENZIE. 

